If CONFIG_MIGRATION=n "migrate_page" turns into NULL. This kills ifdef-endif
mess inside definitions of address space operations. But this macro affects
everything with this name, "migrate_page" is too short and generic.
This patch renames it into generic_migrate_page. Fortunately it's used only in
few places. Also here minor update for documentation: a_ops method is called
"migratepage", without underscore, obviously for keeping the macro away.
Signed-off-by: Konstantin Khlebnikov <koct9i@xxxxxxxxx>
---
Documentation/filesystems/vfs.txt | 13 ++++++++-----
fs/btrfs/disk-io.c | 2 +-
fs/nfs/write.c | 2 +-
include/linux/migrate.h | 6 +++---
mm/migrate.c | 10 +++++-----
mm/shmem.c | 2 +-
mm/swap_state.c | 2 +-
7 files changed, 20 insertions(+), 17 deletions(-)
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index 02a766c..a633fa7 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -746,12 +746,15 @@ struct address_space_operations {
Filesystems that want to use execute-in-place (XIP) need to implement
it. An example implementation can be found in fs/ext2/xip.c.
- migrate_page: This is used to compact the physical memory usage.
- If the VM wants to relocate a page (maybe off a memory card
- that is signalling imminent failure) it will pass a new page
- and an old page to this function. migrate_page should
+ migratepage: This is used to compact the physical memory usage.
+ If the VM wants to relocate a page (maybe off a memory card
+ that is signalling imminent failure) it will pass a new page
+ and an old page to this function. migratepage should
transfer any private data across and update any references
- that it has to the page.
+ that it has to the page.
+
+ Filesystem might use here generic_migrate_page if pages have no
+ private data or buffer_migrate_page for pages with buffers.
launder_page: Called before freeing a page - it writes back the dirty page. To
prevent redirtying the page, it is kept locked during the whole
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index a1d36e6..af1a274 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -973,7 +973,7 @@ static int btree_migratepage(struct address_space *mapping,
if (page_has_private(page) &&
!try_to_release_page(page, GFP_KERNEL))
return -EAGAIN;
- return migrate_page(mapping, newpage, page, mode);
+ return generic_migrate_page(mapping, newpage, page, mode);
}
#endif
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 175d5d0..7101a6d 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -1898,7 +1898,7 @@ int nfs_migrate_page(struct address_space *mapping, struct page *newpage,
if (!nfs_fscache_release_page(page, GFP_KERNEL))
return -EBUSY;
- return migrate_page(mapping, newpage, page, mode);
+ return generic_migrate_page(mapping, newpage, page, mode);
}
#endif
diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index a2901c4..0a4604a 100644
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -38,7 +38,7 @@ enum migrate_reason {
#ifdef CONFIG_MIGRATION
extern void putback_movable_pages(struct list_head *l);
-extern int migrate_page(struct address_space *,
+extern int generic_migrate_page(struct address_space *,
struct page *, struct page *, enum migrate_mode);
extern int migrate_pages(struct list_head *l, new_page_t new, free_page_t free,
unsigned long private, enum migrate_mode mode, int reason);
@@ -82,8 +82,8 @@ static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
return -ENOSYS;
}
-/* Possible settings for the migrate_page() method in address_operations */
-#define migrate_page NULL
+/* Possible settings for the migratepage() method in address_operations */
+#define generic_migrate_page NULL
#endif /* CONFIG_MIGRATION */
diff --git a/mm/migrate.c b/mm/migrate.c
index f78ec9b..905b1aa 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -588,7 +588,7 @@ void migrate_page_copy(struct page *newpage, struct page *page)
*
* Pages are locked upon entry and exit.
*/
-int migrate_page(struct address_space *mapping,
+int generic_migrate_page(struct address_space *mapping,
struct page *newpage, struct page *page,
enum migrate_mode mode)
{
@@ -604,7 +604,7 @@ int migrate_page(struct address_space *mapping,
migrate_page_copy(newpage, page);
return MIGRATEPAGE_SUCCESS;
}
-EXPORT_SYMBOL(migrate_page);
+EXPORT_SYMBOL(generic_migrate_page);
#ifdef CONFIG_BLOCK
/*
@@ -619,7 +619,7 @@ int buffer_migrate_page(struct address_space *mapping,
int rc;
if (!page_has_buffers(page))
- return migrate_page(mapping, newpage, page, mode);
+ return generic_migrate_page(mapping, newpage, page, mode);
head = page_buffers(page);
@@ -728,7 +728,7 @@ static int fallback_migrate_page(struct address_space *mapping,
!try_to_release_page(page, GFP_KERNEL))
return -EAGAIN;
- return migrate_page(mapping, newpage, page, mode);
+ return generic_migrate_page(mapping, newpage, page, mode);
}
/*
@@ -764,7 +764,7 @@ static int move_to_new_page(struct page *newpage, struct page *page,
mapping = page_mapping(page);
if (!mapping)
- rc = migrate_page(mapping, newpage, page, mode);
+ rc = generic_migrate_page(mapping, newpage, page, mode);
else if (mapping->a_ops->migratepage)
/*
* Most pages have a mapping and most filesystems provide a
diff --git a/mm/shmem.c b/mm/shmem.c
index 0e5fb22..2e0058e 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -3075,7 +3075,7 @@ static const struct address_space_operations shmem_aops = {
.write_begin = shmem_write_begin,
.write_end = shmem_write_end,
#endif
- .migratepage = migrate_page,
+ .migratepage = generic_migrate_page,
.error_remove_page = generic_error_remove_page,
};
diff --git a/mm/swap_state.c b/mm/swap_state.c
index 3e0ec83..0ac57c4 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -28,7 +28,7 @@
static const struct address_space_operations swap_aops = {
.writepage = swap_writepage,
.set_page_dirty = swap_set_page_dirty,
- .migratepage = migrate_page,
+ .migratepage = generic_migrate_page,
};
static struct backing_dev_info swap_backing_dev_info = {
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>